Ammunition



Patented May 30, 193% TION Willi Briin and James E. Burns, Bridgeport,Conn, assignors to Remington Arms Company, Inc., a corporation ofDelaware 2 Claims.

This invention relates to priming mixtures for ammunition, andcontemplates the use of ingredients which are substantially doublecompounds, including in a single molecule both an 5 oxidizer and a fuel.

The invention likewise contemplates nove methods in the preparation ofpriming mixtures, particularly in the forming or compounding from itsconstituent ingredients in situ in the mixture and during the mixingoperation, of an essential and explosive ingredient of the mixture.

The present application is a division of our prior co-pendingapplication, Serial No. 722,240, filed April 25, 1934, now Patent No.2,116,878,

May 10, 1938.

The usual ammunition priming mixture includes a reaction initiatingexplosive, a fuel, and a separate substance which yields oxygen for thecombustion of the fuel. The fuel and the 29 oxygen-carrier are distinctand difierent materials, and are separated by distances which whileactuallyof small magnitude become of importance when materials mustreact chemically through them. Theoretically, the finer the granulationof the reacting ingredients the more rapid would be their combustion,but actually separate reacting ingredients cannot be granulated below acertain fineness, say 150 or 200 mesh. One reason for this is that thefiner particles do not set up sufiicient friction to initiate thereaction. The ideal priming mixture is one in which the reactingingredients lie in close proximity to each other in the same crystal. Inthe past some efiorts have been made to produce priming compositionsconsisting solely of suchcrystals, but the product has inyariably failedto satisfy other requirements of successful priming. The presentinvention contemplates the use, in a priming mixture including acombustion initiator andlor a frictionator, of a material in which anoxidizer and a fuel are both present in a single crystal. This materialis a reaction product of lead nitrate and lead hypophosphite. 45 Leadnitrate is a compound which is rich in oxygen and yields its oxygen withconsiderable facility at a comparatively low temperature. Leadhypophosphite is deficient in oxygen. When these substances are broughttogether in the presence of moisture a reaction takes place whichresults in a compound apparently having the compositionPb(NO3)2-Pb(H2PO2)2. This compound will be called leadnitrato-hypophosphite. While lead nitrato-hypophosphite alone is quitesensitive to blow, its explosion cannot be depended upon to ignitepowder. Its deficiency ap- 5 pears to be due to the fact that itsdecomposition is accompanied by only a comparatively short flame, andthe evolution of a comparatively small volume of gas. For these reasons,it has been found necessary to include in priming mixtures 10 madetherefrom an explosive combustion initiating ingredient, such as normalor basic lead due to its explosive character, cannot be broken -downinto granulations suitable for use in priming mixtures. For this reason,applicants have devised a novel method which comprises the formation oflead nitrato-hypophosphite from its constituent ingredients in situ inadmixture with the other ingredients of the priming composition.

There is first prepared a dry pre-mix of lead nitrate, leadhypophosphite and the other inert ingredients of the mixture, such aslead sul- 5 phocyanate and ground glass. After these in-.

gredients have been thoroughly mixed while dry wet lead styphnate and asuitable amount of water are added, and the composition is then mixed ina moist pasty condition in a mixing machine. During this mixing, themoistened lead nitrate and lead hypophosphite react to form theexplosive, lead nitrato-hypophosphite, but, due to the continuedagitation, the formation of extended crystals is prevented; theexplosive being formed as small particles suitably distributed andincorporated with the other ingredients of the mixture. The method ofthus preparing a priming material in situ by the reaction of other Imaterials is one which is wholly new to the art. A typical mixture whichhas been found to Lead be especially useful in brass rimflre shellscomprises lead styphnate, lead hypophosphite, lead nitrate, leadsulphocyanate, and glass, in substantially the following proportions:

Preferred,

Parts parts Lead styphnate Lead hypophosphite nitrate The lead styphnatein any of the above mixtures may be replaced by basic lead styphnate.

Basiclead picrate has likewise been found a very desirable explosive, atypical mixture being as follows:

' Per cent Basic lead picrate 30 Lead hypophosphite 12 Lead nitrate. 33

Glass 25 Other explosives or combinations of explosives may likewise beused, as above indicated. Barium nitrate has been added in amounts up to40%, yielding mixtures which for some purposes are very desirable. Leadperoxide has likewise been found useful as a supplemental oxidizingingredient. The presence of lead sulphocyanate is I unnecessary, manysuccessful mixtures having areaeee What is claimed is:

1. In the preparation of an ammunition primin'g composition whichcomprises an admixture of lead nitrato-hypopho'sphite with inexplosiveingredients selected from the groups of known oxidizers, fuels andabrasives, the method which comprises the compounding of said leadnitratohypophosphite from lead nitrate and lead hypophosphite in situ inadmixture with said inexplosive ingredients and in relatively smallgrains separated by said inexplosive ingredients by mechanically mixingthe requisite quantities of said inexplosive ingredients and said leadnitrate and lead hypophosphite in a moistened condition, and continuingsuch mechanical mixing until the reaction between said lead nitrate' andlead hypophosphite resulting in the formation of leadnitrate-hypophosphite is substantially complete.

2. In the preparation of an ammunition priming composition whichcomprises an admixture of lead nitrate-hypophosphite with an oxidizerand an abrasive, the method which comprises the compounding of said leadnitrato-hypophosphite from lead nitrate and lead hypophosphite in situin admixture with said oxidizer and abrasive and in relatively smallgrains separated by said oxidizer and abrasive by mechanically mixingthe requisite quantities of said oxidizer and abrasive with reactingquantities of lead nitrate and lead hypophosphite in a moistenedcondition and continuing such mechanical mixing until the reactionbetween said lead nitrate and lead hypophosphite resulting in theformation of lead nitrato-hypophosphite is substantially complete.

JAMES E. BURNs. WILLI BRiiN.

